The coalition, which includes California Sportfishing Protection Alliance, Friends of Butte Creek, Friends of the River, Institute for Fisheries Resources, Northern California Council of the Federation of Fly Fishers, Pacific Coast Federation of Fishermen’s Associations, and Sacramento River Preservation Trust, represented by Earthjustice, sent a formal notice to warn FERC that the coalition plans to file suit over ongoing violations of the federal Endangered Species Act stemming from PG&E's operation of the DeSabla – Centerville hydroelectric project on Butte Creek.

PG&E is licensed by FERC to generate electricity using Butte Creek waters. The utility's water diversions from the creek have greatly reduced the available deep, cold pools of water needed by the protected salmon to hold through the summer until they spawn in the early fall. Low flows and high water temperatures led to massive fish kills in Butte Creek in 2002 and 2003. Estimated numbers of adult spring-run Chinook returning to Butte Creek fell from nearly 17,000 in 2005 to 2,561 in 2009.

Spring-run Chinook salmon are so named because they migrate as adults from the ocean to their birth streams during the spring when water flows are high, allowing them access to higher elevation pools where they wait out the summer to lay their eggs in the fall. Spring-run can only survive in creeks and streams fed by cold snowmelt or cold springs in order to withstand high summer temperatures. This severely limits the remaining stream and creek habitat still suitable for spring run survival. Butte Creek has by far the largest remaining wild spring-run chinook salmon population in the Central Valley. The species is believed to have gone extinct in the southern portion of its range in the San Joaquin River system, and clings to survival with small runs in a few other Sacramento River tributaries in addition to Butte Creek. It was listed as threatened under the federal Endangered Species Act in 1999.

Allen Harthorn of Friends of Butte Creek said, "Enormous efforts were made to bring the spring-run Chinook back from the brink of extinction, including the removal of several dams on lower Butte Creek. FERC should have consulted formally with the National Marine Fisheries Service to assess the impacts of the DeSabla-Centerville hydroelectric project on the spring-run long ago. Since no consultation has been completed, the project does not have an incidental take permit required by the Endangered Species Act."

During the spring, summer, and early fall months, adult spring-run Chinook occupy approximately ten miles of holding and spawning habitat in Butte Creek. Fish habitat conditions in this section of Butte Creek, including water temperature and level of flow, are controlled by operation of the DeSabla-Centerville hydroelectric project. Conservation and fishing groups believe the licensing agency, FERC, and the operator, PG&E, should ensure that hydropower operations do not harm the spring-run or degrade their holding and spawning habitat.

A major obstacle to fish restoration is Centerville Head Dam, located on Butte Creek 300 yards below DeSabla Powerhouse. The head dam almost completely blocks salmon from reaching the creek's upper watershed. PG&E’s application for a new FERC license submitted in 2007 proposes no alteration of the dam or mitigation for the loss of habitat that it causes.

"The fish kills of 2002 and 2003 have been echoed in lower spring-run numbers in subsequent years," said Trent Orr, an attorney from Earthjustice who is representing the coalition. "The Butte Creek spring run has dwindled to a tiny fraction of its numbers a decade ago. The species cannot withstand more losses due to PG&E's diversions."

John Beuttler of the California Sportfishing Protection Alliance said, "Our once great spring-run salmon have been virtually eliminated from the Sacramento River and now survive primarily by hanging on in Butte Creek, with much smaller wild populations in two other tributaries. The little that is left of this highly prized salmon is of great importance to anglers and Native Americans, as it represents a unique element of our natural heritage that can be brought back from the path to extinction and fostered to a healthy, sustainable population in Central Valley rivers and streams."

"The spring-run chinook salmon of Butte Creek represent one of the last intact wild runs of this magnificent fish,” said Zeke Grader of the Pacific Coast Federation of Fishermen’s Associations. “Federal agencies have got to consider carefully any operating permits that could be modified to improve the health of this family of salmon – once the largest stock of Chinook salmon in the Central Valley."